I am playing with 40 unit stacks, so my armies are larger, but I never run into this much of a problem with other factions.
I've just hit the first reforms, thinking that would help, but alas, I still can't recruit Spartans in any real numbers. My primary army has five units of Spartans, and I can't recruit anymore. Even after tens of turns I can't get the population over 400 Homoioi in Sparta.
Even Perioikoi are dangerously limited in most places. One of my armies is made up entirely of mercenaries (love the mercenary changes in the latest version, I can actually keep them around now!) but Im running out of xenoi in most of my regions too.
The only thing I have in abundance are helots, but helots are useless.
I understand Sparta is supposed to have a manpower problem, but I didn't expect one this severe. Is 90% of each army really supposed to be made up of mercenaries, or am I doing something wrong?
EDIT: Alternative question, how would I go about increasing Xenoi population in core provinces? In Thracia I've built Thracian settlements and kept the local culture intact, so I have plenty of auxiliaries there, but I was hoping to be able to recruit Macedonian pikes. The abundance of my culture and inability to build Macedonian settlements really limits what I can do to grow the xenoi population.